Grapevine Police Dept. PIO Sgt. Robert Eberling speaks to the press at a mobile police command center in a parking lot in Grapevine, Texas, Tuesday.
A manhunt is under way for Alberto Morales, a prisoner convicted of kidnapping and sexual assault, who stabbed one of two police escorts and escaped in the Dallas area as he was being transferred from Florida to Nevada, police said.

MIAMI — A manhunt is under way for a prisoner convicted of violent sexual assaults who stabbed one of two police escorts and escaped in the Dallas area as he was being transferred from Florida to Nevada, police said Tuesday.

Alberto Morales, 42, stabbed the officer once in the neck and three times in the back Monday night outside a Walmart in Grapevine, police said. Grapevine Police Sgt. Robert Eberling said Morales is believed to have used his eyeglasses in the assault.

Miami-Dade Police Detective Jaime Pardinas, a 54-year-old who has been on the force for 28 years, is in serious but stable condition.

Pardinas and Detective David Carrero were scheduled to fly with Morales to Nevada, where he was to serve a sentence of 30 years to life for a conviction of sexual assault with a weapon. But the officers and Morales weren’t allowed to get back on the plane during a layover in Texas because of the inmate’s erratic behavior, authorities said.

During the first leg of the flight, Morales was “bumping his head against a passenger seat in front of him, so he was doing a lot of crazy, unusual things that just disrupted the entire flight,” said Miami-Dade Police Director J.D. Patterson Jr.

Miami-Dade Police Deputy Director Juan Perez said that it is out of the ordinary, but that airlines occasionally ask officers and their escorted inmates to leave because of liability issues.

The detectives were then forced to rent a vehicle at Dallas-Fort Worth International Airport with the intention of driving the nearly 1,200 miles to their destination. Miami police said there are clear policies about transporting inmates across state lines, but didn’t discuss details other than to say two officers must be present.

The officers stopped to use the restroom at the store late Monday night and were waiting for a third officer to meet them to help with the rest of the trip. While Carrero was inside the store, Morales got hold of a sharp object, stabbed Pardinas and fled, authorities said.

“He was handcuffed. We don’t know how he got the handcuffs free,” Patterson said.

It’s unclear if Morales’ hands were cuffed in front or behind him or if he was shackled. Miami police also declined to speculate on how Morales obtained the object he used to stab the officer. Morales, who was born in Cuba, is believed to have run away.

Police in Grapevine, northwest of Dallas, said they believe Morales is still on foot somewhere nearby and are pursuing several leads, department spokesman Sgt. Robert Eberling said. A $10,000 reward has been set for any information leading to his arrest. The local school district has locked all exterior doors, but classes were running normally.

Longtime Las Vegas defense attorney Marc Saggese, who represented Morales in a Nevada criminal case, said his client claimed he suffered a severe brain injury when he was hit in the head with a baseball bat at 17 years old.

Morales said he heard voices and had trouble controlling impulses.

“He said that ever since that attack and subsequent surgeries he has been struggling with demons in his head,” Saggese said.

While in a jail medical ward, Morales mutilated his genitals and scrawled words in blood on the wall. He underwent a psychological examination by doctors at a Nevada state mental hospital in Sparks, but he was found competent to stand trial, the attorney said.

Morales eventually pleaded guilty in 2008 to sexually assaulting a woman at an apartment blocks away from the Las Vegas Strip in 2003. The woman told police a man jumped from her closet in the middle of the night, held a gun to her face, blindfolded her, attacked her several times and left after telling her he would kill her if she called police, according to Clark County District Court documents.

Following his conviction in Las Vegas, Morales was sent to Florida to face prior charges, Las Vegas police Officer Laura Meltzer said.

Back in Miami, Morales was sentenced to 10 years in prison in December after pleading guilty to sexual battery with a deadly weapon, burglary with assault and kidnapping stemming from 2003. He broke into a Miami-area home, pulled out a butcher knife and raped two women, according to a police report.